ISO 12251:2017

Diesel engines — Clamp mounted CR fuel injectors — Mounting dimensions

ISO 12251 specifies dimensional requirements for clamp mounted CR fuel injectors and their corresponding cylinder head features in diesel engines. According to the injector nozzle capnut, the clamp mounted CR fuel injectors can be divided into two types: a) Type A, where the nozzle capnut is straight (see Figure 4); b) Type B, where the nozzle capnut is stepped (see Figure 5). Each clamp mounted CR fuel injector type is subdivided by a series of different sizes. NOTE This differentiation corresponds to the relationship between the two guide diameters of the clamp mounted CR fuel injectors.

Moteurs diesels — Injecteurs de combustible pour rampe commune fixée par patte — Dimensions de montage

General Information

• Status: Published
• Publication Date: 03-Oct-2017
• ICS: 43.060.40 - Fuel systems
• Technical Committee: ISO/TC 22/SC 34 - Propulsion, powertrain and powertrain fluids
• Drafting Committee: ISO/TC 22/SC 34/WG 2 - Injection equipment
• Current Stage: 9092 - International Standard to be revised
• Completion Date: 01-Nov-2023

Relations

• Revises: ISO 12251:2011 - Diesel engines — Clamp mounted CR fuel injectors — Mounting dimensions
• Effective Date: 14-Nov-2015

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 12251
Second edition
2017-09
Diesel engines — Clamp mounted CR
fuel injectors — Mounting dimensions
Moteurs diesels — Injecteurs de combustible pour rampe commune
fixée par patte — Dimensions de montage
Reference number
ISO 12251:2017(E)
©
ISO 2017

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ISO 12251:2017(E)

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ii © ISO 2017 – All rights reserved

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ISO 12251:2017(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
4 General requirements . 3
4.1 Clamp mounting arrangement . 3
4.2 Injector guiding dimensions. 4
4.3 Concentricity of the nozzle shaft . 4
4.4 High pressure connector . 5
5 Dimensions and tolerances . 6
5.1 Type A, clamp mounted CR fuel injectors with straight capnut . 6
5.2 Type B, clamp mounted CR fuel injectors with stepped capnut . 8
6 Other specifications .10
7 Designation .10
Bibliography .11
© ISO 2017 – All rights reserved iii

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ISO 12251:2017(E)

Foreword
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electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the differen
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